Nowadays, charged particle beam devices, such a scanning electron microscope (SEM) and an FIB (FIB: focused ion beam) device, are used for the processing, observation, and the like of semiconductor devices and other microdevices. Accordingly, there is a growing importance of processing technology that is non-damaging or less damaging to a sample or of technology that allows observation of the structure and shape of a sample surface under a non-damaging or less damaging condition. Here, the FIB device refers to a device for causing a phenomenon known as ion sputtering in which atoms in a surface are made to spring out into a vacuum by irradiating a focused ion beam to a site desired to be processed. In the FIB device, the same ion beam as used at the time of processing is used also at the time of setting a prearranged location to be processed. Thus, a location to be processed is specified on the basis of an FIB image obtained by ion beam scanning. It has been revealed, however, that the ion beam used when setting the prearranged location to be processed also causes ion sputtering as it does at the time of processing, thus causing damage to a sample.